Suction lipectomy or lipolysis is a surgical procedure for removing fatty tissue and fatty tumors from localized areas of the human body through small incisions that can be easily concealed. The surgical procedure customarily employed requires an incision in the skin to expose the fatty tissue. The tip of a cannula is then inserted into the incision and manually directed by the surgeon towards the desired area of the body. By guiding the tip through the fatty tissue while simultaneously applying suction through a longitudinal passage extending through the cannula in communication with the tip, fat is surgically aspirated from the body. For adequate aspiration, approximately 15-20 strokes of the tip through the fatty tissue are often necessary.
FIG. 1 is an illustration of a conventional cannula 10 used for suction lipectomy having a tip 12 and a handle 14 formed at opposite ends thereof. Tip 10 has a hole 16 communicating with a central longitudinal passage 19 extending through the cannula for connection to a suction means 20 in a well known manner. To remove a desired amount of fat from fatty tissue 22 (see FIGS. 2 and 3), an incision 24 is first made in skin 26 to expose the tissue. Tip 10 is then inserted through incision 24 into tissue 26. By gripping handle 14 to move tip 12 through the fatty tissue in continuous reciprocating strokes (see arrows A and A') while applying suction, fat is surgically aspirated through hole 16 and passage 18. After a sufficient number of strokes by the surgeon, the original thickness T of fatty tissue is reduced to a lesser thickness T' (see FIG. 3A).
Because suction lipectomy is essentially cosmetic surgery, considerable surgical skill is necessary to repetitively guide tip 12 in directions A, A' to leave an even layer of tissue intact. This requires guiding tip 12 at a constant depth beneath the skin. Otherwise, different thicknesses of remaining tissue will cause permanent indentations 28 to appear in the skin following surgery (see FIG. 3A), which can be very unsightly. Unfortunately, however, the results frequently obtained with suction lipectomy are of the type shown in FIG. 3A, since the surgeon does not always know or cannot maintain the precise depth at which he guides tip 12 through the tissue. Further, since the surgeon must guide the tip in directions A,A', there is a tendency during the stroke to rotate (arrows B,B') the cannula about its longitudinal axis, causing hole 16 to move above or below the desired depth. Even if the surgeon possesses sufficient skill to guide tip 12 at constant depth, the large number of repetitive strokes necessary for adequate aspiration renders the surgical procedure fatiguing to the surgeon, possibly resulting in momentary loss of control while guiding the cannula.
It is equally important that the surgeon avoid excessive penetration of the cannula tip through the fatty tissue; otherwise, damage to vital organs can occur.
It is accordingly an object of the present invention to provide an improved cannula that is easily guided by the surgeon at a constant depth so that a desired amount of fatty tissue is surgically aspirated while leaving an even thickness layer of tissue intact.
Yet a further object is to provide a cannula that is easy for the surgeon to manipulate, rendering lipolysis less fatiguing to the surgeon to improve safety.
A further object is to provide a cannula that is simple in design and economical to manufacture.
Still another object is to provide a cannula having means preventing excessive penetration of the cannula tip into the body, avoiding possible damage to vital organs.